Can we code rules for an agent in python language other than predicate calculus?
You could formulate the problem of predicting disease severity as a classification one, you give the algorithm those 900 attributes and their corresponding labels (severe/not severe) after training, you give it a new data point with just the 900 attributes, it returns the correct label severe or not.

There is an enormous number of algorithms in the ML literature for classification, some of them formulate the problem explicitly as learnable rules, i.e. let the machine figure out the rules given the attributes.


Classification and Regression Trees by Breiman et al (1984)
Random forest by Ho in 1995
XGBoost